1. Field of the Invention
The present invention relates to a watertight mobile terminal apparatus.
2. Description of the Related Art
Conventionally, telephone calls and transmission and reception of electronic mails using a cellular phone, and the like are widely used for communication with members of a family and friends. By using communication means such as telephone and electronic mail, one can easily contact any distant members of his or her family and friends when desired.
Further, in recent years, cellular phone and PDA (Personal Digital Assistant) are utilized not only as simple communication means, but also as image taking apparatuses for taking images of subjects, computers for viewing Web sites, alarm clocks used on the road, or the like. With the increase in the variety of uses for the mobile terminal apparatus, the number of various electronic parts mounted on the mobile terminal apparatus has increased and it is necessary to provide the mobile terminal apparatus with watertight function. Particularly, it is required that a battery pack can be easily removed and reliably shielded from water, because the battery pack is connected to various electronic parts in the mobile terminal apparatus and may be removed by a user.
In this respect, in Japanese Patent Laid-Open No. 2002-353647, a watertight apparatus is described in which an opening section provided in a housing is closed by a rotationally-locked lid with an intervening rubber packing. By fitting a battery pack in the opening section of the housing, the battery pack can be removably attached to the housing and reliably shielded from water.
However, in the technique described in Japanese Patent Laid-Open No. 2002-353647, it is necessary to provide a knob to be pinched by the user on the rotationally-locked lid. Further, it is necessary to make the lid large so that children and elderly persons can also easily rotate the lid with small force, which results in a problem of size increase of the apparatus. Moreover, it is necessary to tightly close the lid with a thick intervening packing in order to reliably shield the inside of the opening from water, which results in a problem of deterioration of user operability.